Do your homework before installing tile drainage

Finding out what constitutes a wetland and finding a suitable outlet for drained water are two key considerations

Two slides of the same land from the geodiscoveralberta.ca website: The lower ‘wetlands turned on’ slide shows a potentially much larger wetland area, which is apparent in the upper photo. What constitutes a permanent or semi-permanent wetland can only be determined by a wetland scientist, but if they aren’t considered ephemeral, a costly environmental impact assessment is required before any drainage can be installed. Photo:
geodiscoveralberta.ca

Tile drainage is becoming increasingly popular among Alberta producers concerned about losing valuable land and inputs to excess water.

Although tile drainage can be beneficial, it is not without its dangers if a system is designed incorrectly — or if producers don’t know the rules.

In Alberta, tile drainage systems — like all drainage or water diversions — are regulated under the Water Act and enforced by Alberta Environment and Parks, which classifies water bodies according to their permanence as well as specific soil and vegetation characteristics.

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Wetlands are a prime consideration for provincial regulators, said Tim Tuchscherer, operations manager with Terra Drainage Solutions, an all-in-one tile drainage service based in the central Alberta village of Linden. And because what Alberta Environment considers a wetland may not always line up with the landowner’s opinion, it pays to do your homework before embarking on a potentially costly tile drainage project.

“A lot of people may be surprised at what may be considered a wetland,” said Tuchscherer. “A lot of water bodies that look very temporary may actually be identified as wetlands.”

Environmental assessment?

Tile drainage is essentially the use of subsurface tubes to remove excess moisture from topsoil. It’s a practice that, in Alberta at least, is still suffering growing pains. There has been some blowback against it, with some early adopters being retroactively hit with penalties for non-compliance after the Alberta Wetland Policy was implemented in 2014. However, producers’ rights and responsibilities are now fairly well laid out, said Tuchscherer.

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His company focuses on draining water bodies that are only wet for a brief period of time, usually after heavy precipitation. These are known as ephemeral water bodies and are exempt from the Alberta Wetland Policy.

Draining water bodies that fall under that policy can be a costly and complicated process, he said.

“Anybody can drain a wetland if you do the right applications and processes,” said Tuchscherer. “However, if you’re draining anything beyond an ephemeral water body, it requires an environmental impact assessment, which adds a lot of cost to the project. The landowners will also have to pay compensation for any area of wetland they drain above and beyond ephemeral water bodies.

“I usually advise clients that if it’s anything beyond an ephemeral water body that it will cost them an awful lot of money and will take an awful long time and probably won’t be worth it in the long run.”

Plan ahead

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Tuchscherer recommends starting the application process as soon as possible, which means submitting an application at least three months in advance to allow time for approval by all the relevant regulatory bodies. That often means submitting an application in early summer.

“We probably do 75 per cent of our work in the fall after harvest mainly out of convenience for landowners, although we can do it any time the ground is not frozen,” said Tuchscherer. “There’s a small window prior to seeding or just after seeding when, if it’s dry enough, we can get in and do some work.”

The first step is to get an idea of what’s on the land and below the surface. Terra Drainage Solutions uses several publicly available web mapping applications such as Google Earth (www.google.ca/earth) and AbaData (www.abadata.ca) to identify water bodies and potential outlets as well as obstacles such as high-pressure pipelines.

“Obviously we don’t want to be striking any of those with our equipment when we do our installation,” said Tuchscherer. “To cross those lines we have to get a crossing agreement with the owner of the buried facility. This usually requires another permit.”

GeoDiscover Alberta (www.geodiscoveralberta.ca) — a mapping service provided by Alberta Environment — marks every water body that would fall under the criteria of a wetland according to the department’s definitions. The results can be surprising to landowners, said Tuchscherer. “Some farmers would say, ‘That’s a wetland and nothing else on there is a wetland,’ so when you turn on that layer of inventory you can get kind of an interesting result.”

The next step is deciding whether the project is viable based on the results of a topographical survey. This is done using a combination of Real Time Kinematik (RTK) GPS, drone technology, or Light Distance and Ranging (LiDAR) data collected over large areas with a helicopter or fixed-wing aircraft.

“We take that and turn it into a digital terrain model, basically a canvas we design our tile drainage system on. When we submit our application that contour map is submitted as well. Dated aerial photos give the government reference as to how frequently that particular area is wet.”

Alberta considerations

Designing a tile drainage plan in Alberta is often a lot less straightforward than in other provinces, he added.

“In Alberta we have a lot of rolling country and potholes, making it challenging to gather water from lower areas and move it away.”

Finding outlets for the water on a rolling landscape can be challenging. In some cases, the producer needs to get consent from neighbours to drain onto their property.

“Sometimes there’s just no place to put water — it just pools up and the outlet we would like to use won’t work because of elevation or whatever,” said Tuchscherer.

Also, don’t expect much co-operation from local municipalities when it comes to draining into a county ditch, he said.

“Any of the counties I’ve dealt with will not let us drain into a ditch.”

The final step is to submit an application, including any consent forms from neighbours, to one of Alberta Environment’s four offices in the province.

If approved, the installation of drainage tile can begin. Tuchscherer’s company typically spaces tiles 50 feet apart and 30 inches underground using a GPS-guided, pull-type plow.

“The 50-foot spacing will give you a three-eighths of an inch drainage coefficient, which means you can expect to remove three-eighths of an inch of water in 24 hours,” he said. “It’s not extremely fast but it’s effective.

“Drainage doesn’t happen overnight but having the tile in the ground will lower the water table. Precipitation will eventually wash salt in the soil down below the water table. It could take a couple of years before you see a real improvement. A little patience would be advised.”

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